US8255000B2 - Process for computing a frequency offset for a UMTS communication system based on the CPICH pilot signals - Google Patents
Process for computing a frequency offset for a UMTS communication system based on the CPICH pilot signals Download PDFInfo
- Publication number
- US8255000B2 US8255000B2 US13/322,629 US201013322629A US8255000B2 US 8255000 B2 US8255000 B2 US 8255000B2 US 201013322629 A US201013322629 A US 201013322629A US 8255000 B2 US8255000 B2 US 8255000B2
- Authority
- US
- United States
- Prior art keywords
- txd
- notxd
- conj
- avr
- exp
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 40
- 230000008569 process Effects 0.000 title claims abstract description 30
- 238000004891 communication Methods 0.000 title claims abstract description 12
- DWPVVZZGGGCRRM-UHFFFAOYSA-N (4-methoxyphenyl)-(4-methylpiperazin-1-yl)methanone Chemical compound C1=CC(OC)=CC=C1C(=O)N1CCN(C)CC1 DWPVVZZGGGCRRM-UHFFFAOYSA-N 0.000 claims description 8
- 238000012545 processing Methods 0.000 claims description 7
- 238000007781 pre-processing Methods 0.000 claims description 5
- 238000009472 formulation Methods 0.000 claims description 4
- 239000000203 mixture Substances 0.000 claims description 4
- 230000004044 response Effects 0.000 claims description 4
- 238000000926 separation method Methods 0.000 claims description 4
- 238000012360 testing method Methods 0.000 claims description 4
- 230000005540 biological transmission Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000005070 sampling Methods 0.000 description 3
- 238000012935 Averaging Methods 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 230000006399 behavior Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 230000001934 delay Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000000284 extract Substances 0.000 description 1
- 238000005562 fading Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/0014—Carrier regulation
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/0202—Channel estimation
- H04L25/0224—Channel estimation using sounding signals
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/0014—Carrier regulation
- H04L2027/0044—Control loops for carrier regulation
- H04L2027/0063—Elements of loops
- H04L2027/0065—Frequency error detectors
Definitions
- the invention relates to the field of wireless communication and more particularly to a process for estimating the frequency offset in third generation wireless communication systems, particularly for UMTS.
- Universal Mobile Telecommunications Systems is based on the W-CDMA technology and is in the heart of the 3G communication networks providing packet based transmission of text, digitized voice, and multimedia data at rates up to 2 Megabits per second.
- one base station of such a communication systems may comprise two emitting antennas each transmitting one signal comprising one corresponding Common Pilot CHannel (CPICH).
- CPICH Common Pilot CHannel
- FIG. 1 This figure represents the pattern of the transmitted CPICH pilots' sequence.
- Those two pilot signals which are transmitted by the base station are used for the determination of the channel characteristics but also for estimating the frequency offset between the base station reference clock and the internal clock of the User Equipment (UE).
- the received signal corresponding to the transmission of the k th pilot sample in the absence of frequency offset is given by:
- r ⁇ [ k ] ( 1 + j ) ⁇ ( h 1 ⁇ [ k ] + ( - 1 ) ⁇ k + 1 2 ⁇ ⁇ h 2 ⁇ [ k ] ) + n ⁇ [ k ] while when the UE is subject to a frequency offset with respect to the base station, the received signal is then
- r ⁇ [ k ] ( 1 + j ) ⁇ ( h 1 ⁇ [ k ] + ( - 1 ) ⁇ k + 1 2 ⁇ ⁇ h 2 ⁇ [ k ] ) ⁇ exp ⁇ ( j ⁇ ⁇ 2 ⁇ ⁇ ⁇ ⁇ ⁇ k ⁇ ⁇ ⁇ ⁇ fT + ⁇ 0 ) + n ⁇ [ k ]
- ⁇ f is the frequency offset
- T is the time duration between two consecutive samples
- ⁇ 0 is an initial phase rotation.
- T is the time between two consecutive CPICH pilots.
- T 1 15 ⁇ 10 - 3 seconds, which corresponds to covering a range of frequency offsets from minus to plus 7500 Hz.
- DS direct-sequence
- r[k] is the received signal at the instant k
- R r NoTxd ⁇ r NoTxd ⁇ [ k ] 2 ⁇ ( R S 1 ⁇ S 1 + ( - 1 ) ⁇ k + 1 2 ⁇ ⁇ ( - 1 ) ⁇ k + 2 2 ⁇ ⁇ R D 2 ⁇ D 2 + ( - 1 ) ⁇ k + 2 2 ⁇ ⁇ R S 1 ⁇ D 2 + ( - 1 ) ⁇ k + 1 2 ⁇ ⁇ R D 2 ⁇ S 1 ) + R N s ⁇ N s ⁇ [ k ]
- R r Txd ⁇ r Txd ⁇ [ k ] 2 ⁇ ( R S 2 ⁇ S 2 + ( - 1 ) ⁇ k + 1 2 ⁇ ⁇ ( - 1 ) ⁇ k + 2 2 ⁇ ⁇ R D 1 ⁇ D 1 + ( - 1 ) ⁇ k + 2 2 ⁇ ⁇ R D 1 ⁇ D 1 + ( - 1 ) ⁇
- the estimation is based on one estimator R even,avr computed in accordance with the following formulas:
- ⁇ ⁇ ⁇ f 1 2 ⁇ ⁇ ⁇ ⁇ ⁇ T ⁇ arc ⁇ ⁇ tan ⁇ ( ⁇ m ⁇ ( R even , avr ) ⁇ e ⁇ ( R even , avr ) ) where e(.) and m(.) are respectively the imaginary part and real part operators.
- the frequency offset estimation is based on one estimator R odd,avr computed in accordance with the following formulas:
- the estimation is computed on the basis of both R odd,avr and R even,avr in accordance with the formula: If e ( R odd,avr )
- R R odd,avr +R even,avr
- the invention also provides a process for processing the CPICH pilot signals r(i) received from the two antennas of a base station which involves the steps:
- ⁇ ⁇ ⁇ f 1 2 ⁇ ⁇ ⁇ ⁇ ⁇ T ⁇ arc ⁇ ⁇ tan ⁇ ( ⁇ m ⁇ ( R ) ⁇ e ⁇ ( R ) )
- the invention is particularly suitable for the achievement of a UMTS receiver of a User Equipment (UE) such as a mobile telephone or a Portable Document Assistant.
- UE User Equipment
- FIG. 1 illustrates the structure of the sign patter (applied to (1+j)) of the two CPICH pilots sequences which are used in the UMTS using transmit diversity (TxD)
- FIG. 2 illustrates one embodiment of the method for computing the offset frequency in accordance with the present invention.
- FIG. 3 illustrates the principle of the separation of the two signals transmitted through the two emitting antennas.
- RMSE Root Mean Square Error
- the invention can be implemented in digital electronic circuitry forming a mobile telephone or a Portable Digital Assistant (PDA) including hardware circuits with a combination of firmware and software.
- PDA Portable Digital Assistant
- the method which is proposed is based on the computation of the phase discriminator, that is to say the sum of the autocorrelation of the samples sequence.
- FIG. 1 illustrates the sign pattern (applied to (1+j)) resulting from those formulas.
- h m [k] is the channel gain from antenna m at time instant k and n[k] is the additive Gaussian noise with zero mean and variance ⁇ 2 .
- ⁇ f corresponds to the frequency offset and assumed to be identical for both antennas.
- the method is based on a separation of the received pilot signals from the two transmit antennas—summarized in FIG. 3 —in order to keep the sampling period of the resulting samples equal to T, which is a condition for keeping a relatively wide estimation of frequency offsets.
- R r NoTxd ⁇ r NoTxd ⁇ [ k ] 2 ⁇ ( R S 1 ⁇ S 1 + ( - 1 ) ⁇ k + 1 2 ⁇ ⁇ ( - 1 ) ⁇ k + 2 2 ⁇ ⁇ R D 2 ⁇ D 2 + ( - 1 ) ⁇ k + 2 2 ⁇ ⁇ R S 1 ⁇ D 2 + ( - 1 ) ⁇ k + 1 2 ⁇ ⁇ R D 2 ⁇ S 1 ) + R N s ⁇ N s ⁇ [ k ]
- R r Txd ⁇ r Txd ⁇ [ k ] 2 ⁇ ( R S 2 ⁇ S 2 + ( - 1 ) ⁇ k + 1 2 ⁇ ⁇ ( - 1 ) ⁇ k + 2 2 ⁇ ⁇ R D 1 ⁇ D 1 + ( - 1 ) ⁇ k + 2 2 ⁇ ⁇ R D 1 ⁇ D 1 + ( - 1 ) ⁇
- ⁇ ⁇ ⁇ f 1 2 ⁇ ⁇ ⁇ ⁇ ⁇ T ⁇ arc ⁇ ⁇ tan ⁇ ( ⁇ ⁇ m ⁇ ( R even , avr ) ⁇ ⁇ e ⁇ ( R even , avr ) )
- ⁇ ⁇ ⁇ f 1 2 ⁇ ⁇ ⁇ ⁇ ⁇ T ⁇ arc ⁇ ⁇ tan ⁇ ( ⁇ ⁇ m ⁇ ( R odd , avr ) ⁇ ⁇ e ⁇ ( R odd , avr ) )
- the two discriminators values R even,avr and R odd,avr are accumulated as follows: If e ( R odd,avr )
- R R odd,avr +R even,avr
- the correlation R is passed to the arctan function in order to extract the frequency offset estimate:
- ⁇ ⁇ ⁇ f 1 2 ⁇ ⁇ ⁇ ⁇ ⁇ T ⁇ arc ⁇ ⁇ tan ⁇ ( ⁇ ⁇ m ⁇ ( R ) ⁇ ⁇ e ⁇ ( R ) )
- a step 21 the process extracts the received CPICH signal included in the CPICH channel.
- the signal received at the antenna of the user equipment is properly equalized, de-spreaded and descrambled in accordance with the W-CDMA standard. Such operations are well known to a skilled man and, therefore, do not need further development. It suffices to recall that the received despreaded signal is modulated with the appropriate code in order to extract the predetermined CPICH channel. Such channel generates the sum of the two pilot signals transmitted by the base station.
- step 21 two parallel sequences are performed in order to separate the two pilot channels, with a left branch based on steps 22 - 23 and a right branch based on steps 24 - 25 - 26 .
- step 21 achieves the computation of r NoTxd [k] which was mentioned above:
- Such second intermediate value corresponds to the computation of R r NoTxd r NoTxd [k] mentioned above.
- steps 24 - 25 achieves the computation of the value of r txd [k] which was mentioned above:
- Step 26 achieves the computation of R r Txd r Txd [k] mentioned above
- step 32 the frequency offset estimation is computed as follows:
- ⁇ ⁇ ⁇ f 1 2 ⁇ ⁇ ⁇ ⁇ ⁇ T ⁇ arc ⁇ ⁇ tan ⁇ ( ⁇ ⁇ m ⁇ ( R ) ⁇ ⁇ e ⁇ ( R ) )
- the method which was described above shows a sampling period of T, which allows coverage of possible estimation range for a value of
- FIGS. 4 , 5 and 6 are comparative flow charts allowing comparison of the process of the invention which was described above (and referred to as scheme no 3) with respect of two prior art method, namely scheme 1 and 2.
- RMSE Root Mean Squared Error
- the considered SPW simulations setups are as follows:
Abstract
Description
while when the UE is subject to a frequency offset with respect to the base station, the received signal is then
Where hm[k] corresponds to the channel response from antenna m (m=1, 2) and at the time instant of transmission of the kth pilot, Δf is the frequency offset, T is the time duration between two consecutive samples and φ0 is an initial phase rotation.
where T is the time between two consecutive CPICH pilots. In UMTS
seconds, which corresponds to covering a range of frequency offsets from minus to plus 7500 Hz.
S m [k]=h mexp(jφ 0)(exp(jkΦ)+exp(j(k+2)Φ)),
D m[2k]=h mexp(jφ 0)(exp(jkΦ)−exp(j(k+2)Φ))
N s [k]=n[k]+n[k+2]
N d [k]=n[k]−n[k+2]
R r
R r
where, for m=1,2 and n=1,2
R S
R D
R S
R N
R N
which simplifies to:
where N1 and N2 are respectively the indices of the first and the last CPICH symbols used for the frequency offset estimation. The use of the average tends to attenuate the effect of noise by averaging over several symbols. The frequency offset estimate being provided by the formula:
where e(.) and m(.) are respectively the imaginary part and real part operators. Alternatively, the frequency offset estimation is based on one estimator Rodd,avr computed in accordance with the following formulas:
which simplifies to
where N1 and N2 are respectively the indices of the first and the last pilot symbols used for the frequency offset estimation. The use of the average tends to attenuate the effect of noise by averaging over several symbols. The frequency offset estimate being provided by the formula:
In one particular, embodiment, the estimation is computed on the basis of both Rodd,avr and Reven,avr in accordance with the formula:
If e(R odd,avr)|> m(R odd,avr)|
R=R odd,avr +R even,avr
R=R odd,avr −R even,avr
and the frequency offset estimate being provided by the formula:
The invention also provides a process for processing the CPICH pilot signals r(i) received from the two antennas of a base station which involves the steps:
-
- extracting the received CPICH signal included in the CPICH channel;
- performing a first processing branch (left) comprising the steps of:
- computing a first intermediate value x(i) in accordance with the formula:
x(i)=r(i)+r(i+2) - computing a second intermediate value y(i) derived from the first intermediate value x(i) in accordance with the formula:
y(i)=x(i). x*(i+1) - where x* (i+1) is the complex conjugate of x(i+1)
- computing a first intermediate value x(i) in accordance with the formula:
- performing a second processing branch (right)) comprising the steps of:
- computing a third intermediate value x′(i) in accordance with the formula:
x′(i)=r(i)−r(i+2) - computing a fourth intermediate value t(i) derived from the third intermediate value x′(i) in accordance with the formula:
t′(2k)=x′(2k) and
t′(2k+1)=−x′(2k+1) - computing a fifth intermediate value y′(i) derived from the fourth intermediate value t′(i) in accordance with the formula:
y′(i)=t′(i). t′*(i+1)
- computing a third intermediate value x′(i) in accordance with the formula:
- computing a sixth and seventh intermediate values Z and Z′ in accordance with the formulas:
Z(2k)=y(2k)+y′(2k)
Z′(2k+1)=y(2k+1)+y′(2k+1) - respectively computing an eight and a ninth values S and S′ in accordance with the following formulation:
S=1/N Σ Z(k) for k=1 to N
S′=1/N Σ Z′(k) for k=1 to N - performing a test to determine whether the absolute value of the real part of S′ is superior to the absolute value of the imaginary part of S′ and, in that case, computing (30) a tenth intermediate value R as follows:
R=S′+S
And, conversely if the absolute value of the real part of S′ is inferior to the absolute value of the imaginary part of S′, computing R in accordance with the formula:
R=S′−S
The offset estimation is then simply computed as follows:
S m [k]=h mexp(jφ 0)(exp(jkΦ)+exp(j(k+2)Φ))
D m[2k]=h mexp(jφ 0)(exp(jkΦ)−exp(j(k+2)Φ))
N s [k]=n[k]+n[k+2]
N d [k]=n[k]−n[k+2]
R r
R r
where, for m=1,2 and n=1,2
R S
R D
R S
R N
R N
R even [k]=R r
R odd [k]=R r
(i.e. FO=±1875 or FO=±5625)
If e(R odd,avr)|>| m(R odd,avr)|
R=R odd,avr +R even,avr
R=R odd,avr −R even,avr
x(i)=r(i)+r(i+2)
y(i)=x(i). x*(i+1)
x′(i)=r(i)−r(i+2)
t′(2k)=x′(2k) and
t′(2k+1)=−x′(2k+1)
y′(i)=t′(i). t′*(i+1)
Z(2k)=y(2k)+y′(2k)
Z′(2k+1)=y(2k+1)+y′(2k+1)
S=1/N Σ Z(k) for k=1 to N
S′=1/N Σ Z′(k) for k=1 to N
R=S′+S
R=S′−S
-
- Powers: 0 dB, −10 dB
- Delays: 0 ns, 976 ns
Claims (12)
S m [k]=h mexp(jφ 0)(exp(jkΦ)+exp(j(k+2)Φ))
D m[2k]=h mexp(jφ 0)(exp(jkΦ)−exp(j(k+2)Φ))
N s [k]=n[k]+n[k+2]
N d [k]=n[k]−n[k+2]
R even [k]=R r
R S
R D
R S
R N
R N
R odd [k]=R r
R S
R D
R S
R N
R N
R=R odd,avr +R even,avr
R=R odd,avr −R even,avr
x(i)=r(i)+r(i+2)
y(i)=x(i). x*(i+1)
x′(i)=r(i)−r(i+2)
t′(2k)=x′(2k) and
t′(2k+1)=−x′(2k+1)
y′(i)=t′(i). t′*(i+1)
Z(2k)=y(2k)+y′(2k)
Z′(2k+1)=y(2k+1)+y′(2k+1)
S=1/N Σ Z(k) for k=1 to N
S′=1/N Σ Z′(k) for k=1 to N
R=S′+S
R=S′−S
S m [k]=h mexp(jφ 0)(exp(jkΦ)+exp(j(k+2)Φ))
D m[2k]=h mexp(jφ 0)(exp(jkΦ)−exp(j(k+2)Φ))
N s [k]=n[k]+n[k+2]
N d [k]=n[k]−n[k+2]
R even [k]=R r
R S
R D
R S
R N
R N
R odd [k]=R r
R S
R D
R S
R N
R N
R=R odd,avr +R even,avr
R=R odd,avr −R even,avr
x(i)=r(i)+r(i+2)
y(i)=x(i). x*(i+1)
x′(i)=r(i)−r(i+2)
t′(2k)=x′(2k) and
t′(2k+1)=−x′(2k+1)
y′(i)=t′(i). t′*(i+1)
Z(2k)=y(2k)+y′(2k)
Z′(2k+1)=y(2k+1)+y′(2k+1)
S=Σ Z(k) for k=1 to N
S′=Σ Z′(k) for k=1 to N
R=S′+S
R=S′−S
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP09368017 | 2009-06-02 | ||
EP09368017A EP2259520A1 (en) | 2009-06-02 | 2009-06-02 | Process for computing a frequency offset for a UMTS communication system based on the CPICH pilot signals |
EP09368017.1 | 2009-06-02 | ||
PCT/EP2010/003335 WO2010139458A1 (en) | 2009-06-02 | 2010-06-02 | Process for computing a frequency offset for a umts communication system based on the cpich pilot signals |
Publications (2)
Publication Number | Publication Date |
---|---|
US20120157162A1 US20120157162A1 (en) | 2012-06-21 |
US8255000B2 true US8255000B2 (en) | 2012-08-28 |
Family
ID=41228439
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/322,629 Active US8255000B2 (en) | 2009-06-02 | 2010-06-02 | Process for computing a frequency offset for a UMTS communication system based on the CPICH pilot signals |
Country Status (4)
Country | Link |
---|---|
US (1) | US8255000B2 (en) |
EP (2) | EP2259520A1 (en) |
KR (1) | KR101683937B1 (en) |
WO (1) | WO2010139458A1 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2424067A1 (en) * | 2010-08-26 | 2012-02-29 | ST-Ericsson SA | Power management circuit for a portable electronic device including USB functionality and method for doing the same |
Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1249980A2 (en) | 2001-04-09 | 2002-10-16 | Nippon Telegraph and Telephone Corporation | OFDM signal communication system, OFDM signal transmitting device and OFDM signal receiving device |
JP2004072458A (en) | 2002-08-07 | 2004-03-04 | Nippon Telegr & Teleph Corp <Ntt> | Carrier frequency error estimation circuit and radio signal receiving device |
US20040137851A1 (en) * | 2002-10-29 | 2004-07-15 | Akhter Mohammad Shahanshah | Frequency offset controller |
US20050186924A1 (en) * | 2004-02-11 | 2005-08-25 | Samsung Electronics Co., Ltd. | Apparatus and method for estimating initial frequency offset in an asynchronous mobile communication system |
US20050286611A1 (en) * | 2004-06-25 | 2005-12-29 | Nokia Corporation | System, and associated method, for facilitating broadband multi-carrier transmission |
US20060251190A1 (en) * | 2005-05-05 | 2006-11-09 | Oki Techno Centre (Singapore) Pte Ltd | Frequency offset estimation for DPSK |
US20080151839A1 (en) * | 2003-08-04 | 2008-06-26 | Louis Robert Litwin | Frequency Synchronization During Cell Search in a Universal Mobile Telephone System Receiver |
US20080273635A1 (en) * | 2007-05-03 | 2008-11-06 | Holger Neuhaus | Frequency-offset estimation |
US7643587B2 (en) * | 2003-12-25 | 2010-01-05 | Sanyo Electric Co., Ltd. | Frequency offset estimating method and frequency offset correcting apparatus utilizing said method |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE69925990T2 (en) * | 1998-04-03 | 2006-05-11 | Telefonaktiebolaget Lm Ericsson (Publ) | FLEXIBLE CHANNEL ACCESS PROCESS AND RESOURCE ALLOCATION IN A UNIVERSAL MOBILE PHONE SYSTEM (UMTS) |
WO2003073631A1 (en) * | 2002-02-21 | 2003-09-04 | Analog Devices, Inc. | 3g radio |
US20100093389A1 (en) * | 2008-10-14 | 2010-04-15 | Sony Ericsson Mobile Communications Ab | Responding to a paging request from a gsm network by setting up the call through a umts network |
-
2009
- 2009-06-02 EP EP09368017A patent/EP2259520A1/en not_active Withdrawn
-
2010
- 2010-06-02 WO PCT/EP2010/003335 patent/WO2010139458A1/en active Application Filing
- 2010-06-02 US US13/322,629 patent/US8255000B2/en active Active
- 2010-06-02 KR KR1020117028836A patent/KR101683937B1/en active IP Right Grant
- 2010-06-02 EP EP10728118.0A patent/EP2438727B1/en not_active Not-in-force
Patent Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1249980A2 (en) | 2001-04-09 | 2002-10-16 | Nippon Telegraph and Telephone Corporation | OFDM signal communication system, OFDM signal transmitting device and OFDM signal receiving device |
JP2004072458A (en) | 2002-08-07 | 2004-03-04 | Nippon Telegr & Teleph Corp <Ntt> | Carrier frequency error estimation circuit and radio signal receiving device |
US20040137851A1 (en) * | 2002-10-29 | 2004-07-15 | Akhter Mohammad Shahanshah | Frequency offset controller |
US20080151839A1 (en) * | 2003-08-04 | 2008-06-26 | Louis Robert Litwin | Frequency Synchronization During Cell Search in a Universal Mobile Telephone System Receiver |
US7643587B2 (en) * | 2003-12-25 | 2010-01-05 | Sanyo Electric Co., Ltd. | Frequency offset estimating method and frequency offset correcting apparatus utilizing said method |
US20050186924A1 (en) * | 2004-02-11 | 2005-08-25 | Samsung Electronics Co., Ltd. | Apparatus and method for estimating initial frequency offset in an asynchronous mobile communication system |
US20050286611A1 (en) * | 2004-06-25 | 2005-12-29 | Nokia Corporation | System, and associated method, for facilitating broadband multi-carrier transmission |
US20060251190A1 (en) * | 2005-05-05 | 2006-11-09 | Oki Techno Centre (Singapore) Pte Ltd | Frequency offset estimation for DPSK |
US20080273635A1 (en) * | 2007-05-03 | 2008-11-06 | Holger Neuhaus | Frequency-offset estimation |
Non-Patent Citations (3)
Title |
---|
International Preliminary Report on Patentability for corresponding International Patent Application No. PCT/EP2010/003335, issued Dec. 6, 2011. |
International Search Report issued in corresponding International Patent Application No. PCT/EP2010/003335, mailing date Aug. 16, 2010. |
Written Opinion of the International Searching Authority issued in corresponding International Patent Application No. PCT/EP2010/003335, mailing date Aug. 16, 2010. |
Also Published As
Publication number | Publication date |
---|---|
KR101683937B1 (en) | 2016-12-07 |
KR20120044932A (en) | 2012-05-08 |
EP2438727B1 (en) | 2013-10-23 |
WO2010139458A1 (en) | 2010-12-09 |
EP2438727A1 (en) | 2012-04-11 |
US20120157162A1 (en) | 2012-06-21 |
EP2259520A1 (en) | 2010-12-08 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7561646B2 (en) | Multi-antenna wireless receiver chains with vector decoding | |
US8135091B2 (en) | Method and system for communication in a wireless network | |
US7929937B2 (en) | System and method for blind estimation of multiple carrier frequency offsets and separation of user signals in wireless communications systems | |
US7505864B2 (en) | Speed detection method in communication system, receiver, network element and processor | |
KR101035218B1 (en) | Method and apparatus for clock correction in mimo ofdm | |
US7912162B2 (en) | Initial synchronization for receivers | |
US20070014343A1 (en) | Determination of data rate, based on power spectral density estimates | |
US7532664B2 (en) | Method and apparatus to estimate signal to interference plus noise ratio (SINR) in a multiple antenna receiver | |
US6546026B1 (en) | Multi-diversity synchronization technique for improving synchronization performance in wireless applications over fading channels | |
US7649964B2 (en) | Radio receiver and noise estimated value correction method | |
US20050180518A1 (en) | Preamble for estimation and equalization of asymmetries between inphase and quadrature branches in multicarrier transmission systems | |
EP1679818A1 (en) | Removing bias in a pilot symbol error rate for receivers | |
EP1908195A1 (en) | Speed detection method in communication system, receiver, network element and processor | |
US8255000B2 (en) | Process for computing a frequency offset for a UMTS communication system based on the CPICH pilot signals | |
CN100375571C (en) | WCDMA system access channel frequency deviation estimating method | |
US9203526B2 (en) | Method and system for improved interference cancellation by path selection | |
AU2011213712B2 (en) | Method and System for Communication in a Wireless Network | |
EP2063596B1 (en) | Joint packet detection in a wireless communication system with one or more receiver | |
AU2006284509A1 (en) | Method and system for communication in a wireless network |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: ST-ERICSSON SA, SWITZERLAND Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:ANCORA, ANDREA;TOUFIK, ISSAM;REEL/FRAME:027765/0156 Effective date: 20120210 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
FPAY | Fee payment |
Year of fee payment: 4 |
|
AS | Assignment |
Owner name: ST-ERICSSON SA, EN LIQUIDATION, SWITZERLAND Free format text: STATUS CHANGE-ENTITY IN LIQUIDATION;ASSIGNOR:ST-ERICSSON SA;REEL/FRAME:037739/0493 Effective date: 20150223 |
|
AS | Assignment |
Owner name: OPTIS CIRCUIT TECHNOLOGY, LLC,, TEXAS Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:ST-ERICSSON SA, EN LIQUIDATION;REEL/FRAME:048504/0519 Effective date: 20160831 |
|
AS | Assignment |
Owner name: TELEFONAKTIEBOLAGET L M ERICSSON (PUBL), SWEDEN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:OPTIS CIRCUIT TECHNOLOGY, LLC,;REEL/FRAME:048529/0510 Effective date: 20181130 |
|
MAFP | Maintenance fee payment |
Free format text: PAYMENT OF MAINTENANCE FEE, 8TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1552); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY Year of fee payment: 8 |
|
FEPP | Fee payment procedure |
Free format text: MAINTENANCE FEE REMINDER MAILED (ORIGINAL EVENT CODE: REM.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |